InterPro domain: IPR002227

Tyrosinase ( 1.14.18.1 ) [ 1 ] is a copper monooxygenases that catalyzes thehydroxylation of monophenols and the oxidation of o-diphenols to o-quinols.This enzyme, found in prokaryotes as well as in eukaryotes, is involved in theformation of pigments such as melanins and other polyphenolic compounds.Tyrosinase binds two copper ions (CuA and CuB). Each of the two copper ions hasbeen shown [ 2 ] to be bound by three conserved histidines residues. The regionsaround these copper-binding ligands are well conserved and also shared by somehemocyanins, which are copper-containing oxygen carriers from the hemolymph ofmany molluscs and arthropods [ 3 , 4 ].At least two proteins related to tyrosinase are known to exist in mammals, and include TRP-1 (TYRP1) [ 5 ], which is responsible for the conversion of 5,6-dihydro-xyindole-2-carboxylic acid (DHICA) to indole-5,6-quinone-2-carboxylic acid; and TRP-2 (TYRP2) [ 6 ], which is the melanogenic enzyme DOPAchrome tautomerase ( 5.3.3.12 ) that catalyzes the conversion of DOPAchrome to DHICA. TRP-2 differs from tyrosinases and TRP-1 in that it binds two zinc ions instead of copper [ 7 ].Other proteins that belong to this family are plant polyphenol oxidases (PPO) ( 1.10.3.1 ), which catalyze the oxidation of mono- and o-diphenols to o-diquinones [ 8 ]; and Caenorhabditis elegans hypothetical protein C02C2.1.

1. Protein and active-site structure of tyrosinase. Prog. Clin. Biol. Res. 256, 85-98
2. Albino mutants of Streptomyces glaucescens tyrosinase. Biochem. J. 274 ( Pt 3), 707-13
3. [Blue blood: structure and evolution of hemocyanin] Naturwissenschaften 76, 206-11
4. Cloning and sequencing of Octopus dofleini hemocyanin cDNA: derived sequences of functional units Ode and Odf. Proc. Natl. Acad. Sci. U.S.A. 88, 244-8
5. Tyrosinase related protein 1 (TRP1) functions as a DHICA oxidase in melanin biosynthesis. EMBO J. 13, 5818-25
6. A second tyrosinase-related protein, TRP-2, maps to and is mutated at the mouse slaty locus. EMBO J. 11, 527-35
7. Dopachrome tautomerase is a zinc-containing enzyme. Biochem. Biophys. Res. Commun. 204, 1243-50
8. Cloning and characterization of cDNAs coding for Vicia faba polyphenol oxidase. Plant Mol. Biol. 20, 245-53